Operating method and device for performing open-loop or closed-loop control for a permanent brake system of a vehicle

Patent metadata

Field	Value
Publication number	US-9797316-B2
Application number	US-201615282271-A
Country	US
Kind code	B2
Filing date	Sep 30, 2016
Priority date	Oct 1, 2015
Publication date	Oct 24, 2017
Grant date	Oct 24, 2017

Abstract

An operating method and device for a permanent brake system of a motor vehicle. The brake system includes a primary and a secondary permanent brake. Each brake generates respective adjustable braking torque components. The first primary brake has a response than the second primary brake. A third braking torque component is adjusted by the secondary brake. The permanent-brake braking request is applied by the first primary brake until the braking request exceeds a first threshold. The first threshold corresponds to a value less than or equal to a maximum braking torque generated by the first primary brake. After exceeding the first threshold, a component of the request is applied by the secondary permanent brake. A second threshold value corresponds to a value less than or equal to a braking torque that can be generated when the first primary permanent brake device interacts with the secondary permanent brake.

First claim

What is claimed:

1. An operating method for a control element having a microprocessor configured for open-loop and closed-loop control for a permanent brake system of a motor vehicle having a primary permanent brake and a secondary permanent brake,
the microprocessor is issuing instructions for the method comprising:
generating an adjustable first braking torque component by a first primary permanent brake device of the primary permanent brake;
generating an adjustable second braking torque component by a second primary permanent brake device of the primary permanent brake, wherein the first primary permanent brake device has a more rapid response behaviour compared to the second primary permanent brake device;
adjusting a third braking torque component by the secondary permanent brake;
applying, by the first primary permanent brake device, a permanent-brake braking request in a first time period after activation of a permanent brake mode and until the permanent-brake braking request exceeds a first threshold value (P 1 max ) for the first time period after the activation of the permanent brake mode, wherein the first threshold value (P 1 max ) corresponds to a value that is less than or equal to a maximum braking torque that can be generated by the first primary permanent brake device, and
applying, by the secondary permanent brake, a component of the permanent-brake braking request that exceeds the first threshold value (P 1 max ), after the permanent-brake braking request has exceeded the first threshold value (P 1 max ) for the first time period and as long as the permanent-brake braking request has not yet exceeded a second threshold value after the activation of a permanent brake mode for vehicle deceleration, wherein the second threshold value corresponds to a value that is less than or equal to a braking torque which is the maximum that can be generated when the first primary permanent brake device interacts with the secondary permanent brake.

2. The operating method according to claim 1 , further comprising activating the second primary permanent brake device after the second threshold value is exceeded for the first time after the activation of a permanent brake mode.

3. The operating method according to claim 2 , wherein after the activation of the secondary permanent brake, in case of a subsequent reduction in the permanent-brake braking request, the secondary permanent brake remains activated for longer than the brake devices of the primary permanent brake.

4. The operating method according to claim 1 , wherein
a reduction in the permanent-brake braking request that occurs after activation of the second primary permanent brake device is corrected by the secondary permanent brake and/or the first primary permanent brake device and
the second adjustable braking torque component remains constant until the value of the permanent-brake braking request drops below a value that corresponds to a level of an instantaneously set, second adjustable braking torque component of the second primary permanent brake device.

5. The operating method according to claim 1 , wherein
the first primary brake device comprises an engine exhaust brake for building up an exhaust gas back pressure and decompression brake and/or
the second primary engine brake device generates an engine braking torque by changing a charge pressure of a supercharged internal combustion engine.

6. A device configured to perform one of open-loop control and closed-loop control of a permanent brake system of a motor vehicle,
wherein the permanent brake system has a primary permanent brake and a secondary permanent brake,
wherein the primary permanent brake has a first primary permanent brake device configured to generate an adjustable first braking torque component and a second primary permanent brake device configured to generate an adjustable second adjustable braking torque component, wherein the first primary permanent brake device has a more rapid response behaviour compared to the second primary permanent brake device, and
wherein a third braking torque component is configured to be adjusted by the secondary permanent brake,
wherein the device is configured to:
actuate the primary permanent brake and the secondary permanent brake as a function of a permanent-brake braking request,
wherein the permanent-brake braking request is applied by the first primary permanent brake device in a time period after the activation of a permanent brake mode and until a permanent-brake braking request exceeds a first threshold value (P 1 max ) for the first time after the activation of the permanent brake mode, wherein the first threshold value (P 1 max ) corresponds to a value that is less than or equal to a maximum braking torque that can be generated by the first primary permanent brake device, and
wherein after the permanent-brake braking request has exceeded the first threshold value (P 1 max ) for the first time and as long as the permanent-brake braking request has not yet exceeded a second threshold value after the activation of a permanent brake mode, a component of the permanent-brake braking request that exceeds the first threshold value (P 1 max ) is applied by the secondary permanent brake, wherein the second threshold value corresponds to a value that is less than or equal to a braking torque that is the maximum that can be generated when the first primary permanent brake device interacts with the secondary permanent brake.

7. The device according to claim 6 , wherein the device is configured to activate the second primary permanent brake device after the second threshold value has been exceeded for the first time after activation of a permanent brake mode.

8. The device according to claim 6 , wherein in that the device is configured to actuate the primary permanent brake and the secondary permanent brake such that after the secondary permanent brake has been activated, in case of a subsequent reduction of the permanent-brake braking request, the secondary permanent brake remains activated for longer than the brake devices of the primary permanent brake.

9. The device according to claim 6 , wherein the device is configured to:
correct a reduction in the permanent-brake braking request, occurring after activation of the second primary permanent brake device, by the secondary permanent brake and/or the first primary permanent brake device and
to keep constant a setting of the second adjustable braking torque component until the value of the permanent-brake braking request drops below a value that corresponds to a level of an instantaneously set, second adjustable braking torque component of the second primary permanent brake device.

10. The device according to claim 6 wherein the permanent brake system has a secondary retarder.

11. A utility vehicle, comprising a device configured to perform one of open-loop control and closed-loop control of a permanent brake system of a motor vehicle,
wherein the permanent brake system has a primary permanent brake and a secondary permanent brake,
wherein the primary permanent brake has a first primary permanent brake device configured to generate an adjustable first braking torque component and a second primary permanent brake device configured to generate an adjustable second adjustable braking torque component, wherein the first primary permantent brake device has a more rapid response behaviour compared to the second primary permanent brake device, and
wherein a third braking torque component is configured to be adjusted by the secondary permanent brake,
wherein the device is configured to:
actuate the primary permanent brake and the secondary permanent brake a

Assignees

• Man Truck & Bus Ag

Inventors

• Palm Rüdiger

Classifications

• G06F7/70

  using stochastic pulse trains, i.e. randomly occurring pulses the average pulse rates of which represent numbers {(conversion of analogue signals into stochastic pulse trains and vice versa H03M1/04)} · CPC title

• B60W2540/12

  Brake pedal position · CPC title

• B60W10/196

  acting within the driveline, e.g. retarders · CPC title

• B60T10/00 Primary

  Control or regulation for continuous braking making use of fluid or powdered medium, e.g. for use when descending a long slope · CPC title

• B60W2710/0666

  Engine torque · CPC title